The present invention relates to xcex1,xcex2-fused butyrolactones, to processes for their preparation and to their use as pharmaceuticals.
The amino acid L-glutamate is the most important excitatory neurotransmitter in the brain. Glutamate receptors can be divided into two major classes: 1 ionotropic receptors which control ion channels directly and 2. metabotropic receptors (mGluRs).
Metabotropic glutamate receptors are a heterogeneous class of G-protein-coupled receptors. Pre- and postsynaptically, they modulate the release of glutamate and the sensitivity of the cell to glutamate, respectively. The effects are caused via different second-messenger cascades. This response, in turn, has an effect on the ionotropic glutamate receptors.
Presently, 8 different subtypes of metabotropic glutamate receptors are known, differing in the second-messenger cascade, pharmacology and the localization in the brain (review in: Ann. Rev. Pharmacol. Toxicol. 1997, 37, 205).
The present invention relates to xcex1,xcex2-fused butyrolactones of the general formula (I) 
in which
A represents radicals of the formulae xe2x80x94CH2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94CR4(OH)xe2x80x94 or xe2x80x94(CH2)axe2x80x94CHR5xe2x80x94,
in which
a represents a number 0, 1, 2, 3 or 4,
R4 represents hydrogen or (C1-C6)-alkyl
and
R5 represents phenyl,
or
represents (C2-C8)-alkanediyl, (C2-C6)-alkenediyl or (C2-C6)-alkinediyl,
R1 represents hydrogen, (C3-C6)-cycloalkyl or represents a 5- to 6-membered heterocycle which may contain up to 3 heteroatoms from the group consisting of S, O, N and/or a radical of the formula xe2x80x94NR6,
in which
R6 represents hydrogen or methyl,
or
represents a 5- to 6-membered benzo-fused heterocycle which may contain up to 2 heteroatoms from the group consisting of S, O, N and/or a radical of the formula xe2x80x94NR7, and which may be attached both via the phenyl ring and via the heterocycle,
in which
R7 has the meaning of R6 given above and is identical to or different from this meaning,
or
represents radicals of the formulae 
in which
b and c are identical or different and represent a number 1 or 2,
or
represents (C6-C10)-aryl,
where all of the ring systems listed above are optionally mono- to polysubstituted by identical or different substituents selected from the group consisting of halogen, cyano, nitro, trifluoromethyl, hydroxyl, (C1-C6)-alkoxy, (C1-C6)-alkyl-carbonyloxy and (C3-C6)-cycloalkyl, phenyl, phenoxy, benzyloxy and a 5- to 6-membered aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O, which for their part may be substituted up to three times by identical or different substituents from the group consisting of cyano and halogen,
and/or are substituted by (C1-C6)-alkyl and (C2-C6)-alkylene, which for their part may be substituted by halogen, (C6-C10)-aryl or by radicals of the formula xe2x80x94SR8, xe2x80x94OR9 or xe2x80x94NR10R11 or 
in which
R8 represents (C1-C6)-alkyl or phenyl,
R9 represents hydrogen or (C1-C6)-alkyl,
and
R10 and R11 are identical or different and represent hydrogen, phenyl or (C1-C6)-alkyl, which is optionally substituted by phenyl, which for its part may be mono- to polysubstituted by identical or different substituents from the group consisting of halogen, nitro, hydroxyl and (C1-C6)-alkoxy,
or
R10 and R11 together with the nitrogen atom form a radical of the formula 
in which
G represents an oxygen atom, a xe2x80x94CH2xe2x80x94 group or a radical of the formula xe2x80x94NR12xe2x80x94,
in which
R12 represents hydrogen, phenyl, benzyl, (C1-C6)-alkyl, (C1-C6)-alkoxy-carbonyl or a 5- to 6-membered aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O,
and/or are substituted by groups of the formulae xe2x80x94CO2xe2x80x94R13, xe2x80x94NR14R15, xe2x80x94NR16COxe2x80x94R17, xe2x80x94NR18CO2xe2x80x94R19 and xe2x80x94COxe2x80x94NR20R21,
in which
R13 represents hydrogen, or represents (C1-C9)-alkyl or (C2-C6)-alkenyl, which for their part may be substituted by radicals of the formulae 
(C6-C10)-aryl or by a 5- to 7-membered aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O,
in which
d represents a number 1 or 2,
or
represents (C6-C10)-aryl, which is optionally substituted by phenyl, which for its part may be substituted by cyano or halogen,
R14 and R15 are identical or different and represent hydrogen, (C3-C6)-cycloalkyl, phenyl or (C1-C6)-alkyl, which is optionally substituted by (C3-C6)-cycloalkyl or phenyl, which for its part may be mono- to polysubstituted by identical or different substituents from the group consisting of halogen, hydroxyl or (C1-C6)-alkoxy,
R16 represents hydrogen or (C1-C6)-alkyl,
R17 represents hydrogen, adamantyl, (C3-C8)-cycloalkyl, (C2-C6)-alkenyl or (C1-C12)-alkyl which is optionally substituted by adamantyl, (C3-C6)-cycloalkyl, (C6-C10)-aryl, phenoxy or a 5- to 6-membered aromatic heterocycle having up to 4 heteroatoms from the group consisting of S, N and/or O, where aryl and the heterocycle for their part may be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C6)-alkyl, (C1-C6)-alkoxy, hydroxyl, nitro or halogen,
and/or alkyl is optionally substituted by a radical of the formula 
in which
e represents a number 0 or 1 and
R22 represents (C1-C6)-alkyl or (C6-C10)-aryl, which is optionally mono- to polysubsituted by identical or different substituents from the group consisting of halogen, nitro, hydroxyl and (C1-C6)-alkoxy,
or
represents (C6-C10)-aryl or a 5- to 6-membered aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O, which for their part may optionally be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C6)-alkoxy, (C1-C6)-alkyl, hydroxyl, nitro and halogen,
or
represents a radical of the formula 
in which
L and M are identical or different and represent hydrogen or halogen,
R23 and R24 have the meaning of R10 and R11 given above and are identical to or different from this meaning,
R18 has the meaning of R16 given above and is identical to or different from this meaning,
R19 represents (C3-C8)-cycloalkyl, or
represents (C1-C8)-alkyl or (C2-C8)-alkenyl, which for their part are optionally substituted by substituents selected from the group consisting of halogen, phenyl, hydroxyl, morpholinyl, (C3-C8)-cycloalkyl and by a group of the formula xe2x80x94SiR25R26R27,
in which
R25, R26 and R27 are identical or different and represent (C1-C6)-alkyl,
R20 and R21 are identical or different and represent hydrogen, adamantyl, (C3-C8)-cycloalkyl, phenyl, phenoxy-substituted phenyl or a 5- to 6-membered, aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O, or
represent (C2-C8)-alkenyl, (C1-C12)-alkyl or (C2-C6)-alkinyl, which are optionally substituted by hydroxyl, (C3-C6)-cycloalkyl, (C1-C6)-alkoxy, halogen, hydroxyl, trifluoromethyl, phenyl or by a 5- to 6-membered aromatic heterocycle having up to 3 heteroatoms from the group consisting of S, N and/or O, where the ring systems are optionally substituted up to 2 times by identical or different substituents from the group consisting of (C1-C6)-alkoxy, (C1-C6)-alkoxycarbonyl, halogen, phenoxy, hydroxyl and (C1-C6)-alkyl,
and/or the alkyl listed under R20/R21 is optionally substituted by radicals of the formulae 
in which
R28 and R29 are identical or different and represent hydrogen or (C1-C6)-alkyl,
or
represents a radical of the formula 
in which
R30 has the meaning of R12 given above and is identical to or different from this meaning,
or
R20 and R21 together with the nitrogen atom form a radical of the formula 
in which
Gxe2x80x2 has the meaning of G given above and is identical to or different from this meaning,
R2 and R3 are identical or different and represent hydrogen or (C1-C6)-alkyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34, R35, R36, R37 and R38 are identical or different and represent hydrogen, phenyl or (C1-C6)-alkyl,
and their pharmaceutically acceptable salts.
The compounds according to the invention can exist in stereoisomeric forms which either behave as image and mirror image (enantiomers), or which do not behave as image and mirror image (diastereomers). The invention relates both to the enantiomers or diastereomers and their respective mixtures. Like the diastereomers, the racemic forms can be separated into the stereoisomerically uniform components in a known manner.
Physiologically acceptable salts of the compounds according to the invention can be salts of the substances according to the invention with mineral acids, carboxylic acids or sulphonic acids. Particular preference is given, for example, to salts with hydrochloric acid, hydrobromic acid, sulphuric acid, phosphoric acid, methanesulphonic acid, ethanesulphonic acid, toluenesulphonic acid, benzenesulphonic acid, naphthalenedisulphonic acid, acetic acid, propionic acid, lactic acid, tartaric acid, citric acid, fumaric acid, maleic acid or benzoic acid.
Salts which can be mentioned are salts with customary bases, such as, for example, alkali metal salts (for example sodium or potassium salts), alkaline earth metal salts (for example calcium or magnesium salts) or ammonium salts, derived from ammonia or organic amines, such as, for example, diethylamine, triethylamine, ethyldiisopropylamine, procaine, dibenzylamine, N-methylmorpholine, dihydroabietylamine, 1-ephenamine or methylpiperidine.
In the context of the invention, (C3-C8)-cycloalkyl and (C3-C6)-cycloalkyl represent cyclopropyl, cyclopentyl, cyclobutyl, cyclohexyl, cycloheptyl or cyclooctyl. Preferred examples which may be mentioned are: cyclopropyl, cyclopentyl, cyclohexyl or cycloheptyl.
In general, (C6-C10)-aryl represents an aromatic radical having 6 to 10 carbon atoms. Preferred aryl radicals are phenyl and naphthyl.
In the context of the invention, (C1-C12)-alkyl, (C1-C9)-alkyl, (C1-C8)-alkyl and (C1-C6)-alkyl represent a straight-chain or branched alkyl radical having 1 to 12, 1 to 9, 1 to 8 and 1 to 6 carbon atoms, respectively. Preference is given to a straight-chain or branched alkyl radical having 1 to 6 carbon atoms. Examples which may be mentioned are: methyl, ethyl, n-propyl, isopropyl, t-butyl, n-pentyl and n-hexyl.
In the content of the invention, (C2-C8)-alkanediyl represents a straight-chain or branched alkanediyl radical having 2 to 8 carbon atoms. Preference is given to a straight-chain or branched alkanediyl radical having 2 to 6 carbon atoms, particularly preferably 2 to 4 carbon atoms. Examples which may be mentioned are ethylene, propylene, propane-1,2-diyl, propane-2,2-diyl, butane-1,3-diyl, butane-2,4-diyl, pentane-2,4-diyl, 2-methyl-pentane-2,4-diyl.
In the content of the invention, (C2-C6)-alkenediyl represents a straight-chain or branched alkenediyl radical having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, particularly preferably 3 carbon atoms. Examples which may be mentioned are ethene-1,2-diyl, ethene-1,1-diyl, propene-1,1-diyl, propene-1,2-diyl, propene-1,3-diyl, propene-3,3-diyl, propene-2,3-diyl, but-2-ene-1,4-diyl, pent-2-ene-1,4-diyl, hex-2-ene-1,4-diyl.
In the context of the invention, (C2C6)-alkinediyl represents a straight-chain or branched alkinediyl radical having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, particularly preferably 2 to 3 carbon atoms. Examples which may be mentioned are ethine-1,2-diyl, propine-1,3-diyl, but-2-ine-1,4-diyl, pent-2-ine-1,4-diyl, hex-2-ine-1,4-diyl.
In the context of the invention, (C1-C6)-alkoxy represents a straight-chain or branched alkoxy radical having 1 to 6 carbon atoms. Preference is given to a straight-chain or branched alkoxy radical having 1 to 4 carbon atoms. Examples which may be mentioned are: methoxy, ethoxy, n-propoxy, isopropoxy, t-butoxy, n-pentoxy and n-hexoxy.
In the context of the invention, (C1-C6)-alkoxycarbonyl represents a straight-chain or branched alkoxycarbonyl radical having 1 to 6 carbon atoms. Preference is given to a straight-chain or branched alkoxycarbonyl radical having 1 to 4 carbon atoms. Examples which may be mentioned are: methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl and t-butoxycarbonyl.
In the context of the invention, (C2-C8)-alkenyl and (C2-C6)-alkenyl represent a straight-chain or branched alkenyl radical having 2 to 8 carbon atoms and 2 to 6 carbon atoms, respectively. Preference is given to a straight-chain or branched alkenyl radical having 2 to 4 carbon atoms. Examples which may be mentioned are: vinyl, allyl, isopropenyl and n-but-2-en-1-yl.
In the context of the invention, (C2-C6)-alkinyl represents a straight-chain or branched alkinyl radical having 2 to 6 carbon atoms. Preference is given to a straight-chain or branched alkinyl radical having 2 to 4 carbon atoms. Examples which may be mentioned are: ethinyl, n-prop-2-in-1-yl and n-but-2-in-1-yl.
In the context of the invention, a 5- to 6-membered heterocycle generally represents a 5- to 6-membered, optionally also aromatic, heterocycle which may contain up to 3 heteroatoms from the group consisting of S, O and/or N or a radical of the formula xe2x80x94NH or xe2x80x94NCH3. Examples which may be mentioned are: pyridyl, pyrimidyl, pyridazinyl, thienyl, furyl, pyrrolyl, thiazolyl, oxazolyl, imidazolyl, piperidinyl or morpholinyl. Preference is given to pyridyl, pyrimidyl, pyridazinyl, furyl and thiazolyl.
In the context of the invention, a 5- to 6-membered, benzo-fused heterocycle generally represents a 5- to 6-membered, preferably 5-membered heterocycle having up to 2 heteroatoms from the group consisting of S, O, N and/or a radical of the formula xe2x80x94NH, whose ring carbon atoms are the attachment points for the benzene ring. Examples which may be mentioned are: indolyl, benzimidazolyl, benzothiophenyl, benzofuranyl, benzoxazolyl, quinolyl, quinoxalinyl or quinazolyl. Preference is given to benzimidazolyl, quinolyl, quinoxalinyl, quinazolyl, benzothiophenyl and benzofuranyl.
Preference is given to compounds of the general formula (I) according to the invention,
in which
A represents radicals of the formulae xe2x80x94CH2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94CR4(OH)xe2x80x94 or xe2x80x94(CH2)axe2x80x94CHR5xe2x80x94,
in which
a represents a number 0, 1, 2 or 3,
R4 represents hydrogen or (C1-C4)-alkyl
and
R5 represents phenyl,
or
represents (C2-C6)-alkanediyl, (C2-C4)-alkenediyl or (C2-C4)-alkinediyl,
R1 represents hydrogen, cyclopropyl, cyclopentyl or cyclohexyl, or represents benzofuranyl, benzothiophenyl, benzimidazolyl, thienyl, furyl, quinazolyl, quinoxalinyl or quinolyl,
or
represents radicals of the formulae 
in which
b and c are identical or different and represent a number 1 or 2,
or
represents phenyl or naphthyl,
where all of the ring systems listed above are optionally mono- to polysubstituted by identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, iodine, cyano, nitro, trifluoromethyl, hydroxyl or (C1-C5)-alkoxy, (C1-C5)-alkyl-carbonyloxy, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, phenoxy, pyridyl, pyrimidyl, pyridazinyl, thienyl, furyl or benzyloxy, which for their part may be substituted up to three times by identical or different substituents from the group consisting of cyano, fluorine, chlorine, bromine and iodine,
and/or are substituted by (C1-C5)-alkyl and (C2-C4)-alkenyl, which for their part may be substituted by fluorine, chlorine, bromine, iodine, phenyl, naphthyl or by radicals of the formula xe2x80x94SR8, xe2x80x94OR9 or xe2x80x94NR10R11 or 
in which
R8 represents (C1-C4)-alkyl or phenyl,
R9 represents hydrogen or (C1-C4)-alkyl,
and
R10 and R11 are identical or different and represent hydrogen, phenyl or (C1-C4)-alkyl, which is optionally substituted by phenyl, which for its part may be mono- to polysubstituted by identical or different substituents from the group consisting of fluorine, chlorine, bromine, nitro, hydroxyl and (C1-C4)-alkoxy,
or
R10 and R11 together with the nitrogen atom form a radical of the formula 
in which
G represents an oxygen atom, a xe2x80x94CH2xe2x80x94 group or a radical of the formula xe2x80x94NR12xe2x80x94,
in which
R12 represents hydrogen, phenyl, benzyl, (C1-C4)-alkyl, (C1-C4)-alkoxycarbonyl, pyridyl, pyrimidyl, pyridazinyl or furyl,
and/or are substituted by groups of the formulae xe2x80x94CO2xe2x80x94R13, xe2x80x94NR14R15, xe2x80x94NR16COxe2x80x94R17, xe2x80x94NR18CO2xe2x80x94R19 and xe2x80x94COxe2x80x94NR20R21,
in which
R13 represents hydrogen, or represents (C1-C8)-alkyl or (C2-C5)-alkenyl, which for their part may be substituted by radicals of the formulae 
phenyl, naphthyl, pyridyl, thienyl or furyl,
in which
d represents a number 1 or 2,
or
represents phenyl or naphthyl, which are optionally substituted by phenyl, which for its part may be substituted by cyano, fluorine, chorine or bromine,
R14 and R15 are identical or different and represent hydrogen, cyclopropyl, cyclopentyl, cyclohexyl, phenyl or (C1-C5)-alkyl, which is optionally substituted by cyclopropyl, cyclopentyl, cyclohexyl or phenyl, which for its part may be mono- to polysubstituted by identical or different substituents from the group consisting of fluorine, chlorine, bromine, hydroxyl or (C1-C4)-alkoxy,
R16 represents hydrogen or (C1-C3)-alkyl,
R17 represents hydrogen, adamantyl, cyclopropyl, cyclopentyl or cyclohexyl, or represents (C2-C4)-alkenyl or (C1-C10)-alkyl, which is optionally substituted by adamantyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, phenoxy-naphthyl, pyridyl, thienyl, tetrazolyl or furyl, where the ring systems for their part may be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C4)-alkyl, (C1-C4)-alkoxy, hydroxyl, nitro, fluorine, chlorine and bromine,
and/or alkyl is optionally substituted by a radical of the formula 
in which
e represents a number 0 or 1 and
R22 represents (C1-C4)-alkyl, phenyl or naphthyl, which are optionally mono- to polysubstituted by identical or different substituents from the group consisting of fluorine, chlorine, bromine, nitro, hydroxyl and (C1-C4)-alkoxy,
or
represents phenyl, naphthyl, thienyl, furyl or pyridyl, which for their part may optionally be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C4)-alkoxy, (C1-C4)-alkyl, hydroxyl, nitro, fluorine, chlorine and bromine,
or
represents a radical of the formula 
in which
L and M are identical or different and represent hydrogen, fluorine, chlorine or bromine,
R23 and R24 have the meaning of R10 and R11 given above and are identical to or different from this meaning,
R18 has the meaning of R16 given above and is identical to or different from this meaning,
R19 represents cyclopropyl, cyclopentyl or cyclohexyl, or
represents (C1-C7)-alkyl or (C2-C6)-alkenyl, which for their part are optionally substituted by substituents selected from the group consisting of fluorine, chlorine, bromine, phenyl, hydroxyl, morpholinyl, cyclopropyl, cyclopentyl, cyclohexyl and by a group of the formula xe2x80x94SiR25R26R27,
in which
R25, R26 and R27 are identical or different and represent (C1-C4)-alkyl,
R20 and R21 are identical or different and represent hydrogen, adamantyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, phenoxy-substituted phenyl, pyridyl, furyl, thienyl, thiazolyl or pyrryl, or
represent (C2-C6)-alkenyl, (C1-C10)-alkyl or (C3-C6)-alkinyl, which are optionally substituted by hydroxyl, cyclopropyl, cyclopentyl, cyclohexyl, (C1-C5)-alkoxy, (C1-C6)-alkoxycarbonyl, fluorine, chlorine, bromine, hydroxyl, trifluoromethyl, phenyl, pyridyl, furyl, thienyl or pyrryl, where the ring systems are optionally substituted up to 2 times by identical or different substituents from the group consisting of (C1-C4)-alkoxy, fluorine, chlorine, bromine, phenoxy, hydroxyl or (C1-C4)-alkyl,
and/or the alkyl listed under R20/R21 is optionally substituted by radicals of the formulae 
in which
R28 and R29 are identical or different and represent hydrogen or (C1-C4)-alkyl,
or
represents a radical of the formula 
in which
R30 has the meaning of R12 given above and is identical to or different from this meaning,
or
R20 and R21 together with the nitrogen atom form a radical of the formula 
in which
Gxe2x80x2 has the meaning of C given above and is identical to or different from this meaning,
R2 and R3 are identical or different and represent hydrogen or (C1-C3)-alkyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34, R35, R36, R37 and R38 are identical or different and represent hydrogen, phenyl or (C1-C3)-alkyl,
and their pharmaceutically acceptable salts.
Particular preference is given to compounds of the general formula (I) according to the invention,
in which
A represents radicals of the formulae xe2x80x94CH2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94CR4(OH)xe2x80x94 or xe2x80x94(CH2)axe2x80x94CHR5xe2x80x94,
in which
a represents a number 0, 1, 2 or 3,
R4 represents hydrogen or (C1-C3)-alkyl
and
R5 represents phenyl,
or
represents (C2-C4)-alkanediyl, propenediyl or (C2-C3)-alkinediyl,
R1 represents hydrogen, cyclopropyl or cyclohexyl, or represents benzofuranyl, benzothiophenyl, benzimidazolyl, thienyl, quinazolyl or quinoxalinyl,
or
represents radicals of the formulae 
in which
b and c are identical or different and represent a number 1 or 2,
or
represents phenyl or naphthyl,
where all of the ring systems listed above are optionally mono- to polysubstituted by identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, iodine, cyano, nitro, trifluoromethyl or (C1-C4)-alkoxy, (C1-C4)-alkyl-carbonyloxy, cyclohexyl, phenyl, phenoxy, pyridyl, pyrimidyl, pyridazinyl or benzyloxy, which for their part may be substituted up to three times by identical or different substituents from the group consisting of cyano, fluorine, chlorine, bromine and iodine,
and/or are substituted by (C1-C4)-alkyl and (C2-C3)-alkenyl, which for their part may be substituted by chlorine, bromine, iodine or phenyl or by radicals of the formula xe2x80x94OR9 or xe2x80x94NR10R11 or 
in which
R9 represents hydrogen or (C1-C3)-alkyl,
and
R10 and R11 are identical or different and represent hydrogen, phenyl or (C1-C3)-alkyl, which is optionally substituted by phenyl, which for its part may be substituted by chlorine, bromine, hydroxyl or (C1-C3)-alkoxy,
or
R10 and R11 together with the nitrogen atom form a radical of the formula 
in which
G represents an oxygen atom or a radical of the formula xe2x80x94NR12,
in which
R12 represents hydrogen, phenyl, benzyl, (C1-C3)-alkyl, (C1-C3)-alkoxycarbonyl, pyridyl, pyrimidyl, pyridazinyl or furyl,
and/or are substituted by groups of the formulae xe2x80x94CO2xe2x80x94R13, xe2x80x94NR14R15, xe2x80x94NR16COxe2x80x94R17, xe2x80x94NR18CO2xe2x80x94R19 and xe2x80x94COxe2x80x94NR20R21,
in which
R13 represents hydrogen, or represents (C1-C6)-alkyl or allyl, which for their part may be substituted by radicals of the formulae 
phenyl, naphthyl or pyridyl,
in which
d represents a number 1 or 2,
or
represents phenyl, which is optionally substituted by phenyl, which for its part may be substituted by cyano, chlorine or bromine,
R14 and R15 are identical or different and represent hydrogen, cyclohexyl, phenyl or (C1-C4)-alkyl, which is optionally substituted by cyclopropyl, cyclohexyl or phenyl, which for its part may be mono- to polysubstituted by identical or different substituents from the group consisting of chlorine and (C1-C3)-alkoxy,
R16 represents hydrogen, methyl or ethyl,
R17 represents hydrogen, adamantyl, cyclopentyl or cyclohexyl, or represents (C2-C3)-alkenyl or (C1-C8)-alkyl, which is optionally substituted by adamantyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, phenoxy, thienyl or furyl, where the ring systems for their part may be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C3)-alkyl, (C1-C3)-alkoxy, hydroxyl, nitro, fluorine, chlorine and bromine,
and/or alkyl is optionally substituted by a radical of the formula 
in which
e is a number 0 or 1 and
R22 represents (C1-C3)-alkyl, phenyl or naphthyl, which are optionally mono- to polysubstituted by identical or different substituents from the group consisting of fluorine, chlorine, bromine, nitro, hydroxyl and (C1-C3)-alkoxy,
or
represents phenyl, naphthyl, thienyl or furyl, which for their part may optionally be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C3)-alkoxy, (C1-C3)-alkyl, nitro, fluorine, chlorine and bromine,
or
represents a radical of the formula 
in which
L and M are identical or different and represent hydrogen, fluorine or chlorine,
R23 and R24 have the meaning of R10 and R11 given above and are identical to or different from this meaning,
R18 has the meaning of R16 given above and is identical to or different from this meaning,
R19 represents (C1-C4)-alkyl or (C3-C5)-alkenyl, which for their part are optionally substituted by substituents selected from the group consisting of chlorine, phenyl, hydroxyl, morpholinyl, cyclopropyl, cyclohexyl and by a group of the formula xe2x80x94SiR25R26R27,
in which
R25, R26 and R27 are identical and represent methyl,
R20 and R21 are identical or different and represent hydrogen, adamantyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, phenoxy-substituted phenyl, thiazolyl or pyrryl, or
represent (C2-C3)-alkenyl, (C1-C7)-alkyl or (C3-C5)-alkinyl, which are optionally substituted by hydroxyl, cyclopropyl, cyclopentyl, cyclohexyl, (C1-C3)-alkoxy, hydroxyl, trifluoromethyl, phenyl, pyridyl, furyl, thienyl or pyrryl, where the ring systems are optionally substituted up to 2 times by identical or different substituents from the group consisting of (C1-C3)-alkoxy, (C1-C6)-alkoxycarbonyl, fluorine, chlorine, bromine, phenoxy, hydroxyl and (C1-C3)-alkyl,
and/or the alkyl listed under R20/R21 is optionally substituted by radicals of the formulae 
in which
R28 and R29 are identical or different and represent hydrogen or (C1-C3)-alkyl,
or
R20 or R21 represents a radical of the formula 
in which
R30 has the meaning of R12 given above and is identical to or different from this meaning,
or
R20 and R21 together with the nitrogen atom form a radical of the formula 
in which
Gxe2x80x2 has the meaning of G given above and is identical to or different from this meaning,
R2 and R3 are identical or different and
represent hydrogen or methyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34, R35, R36, R37 and R38 are identical or different and represent hydrogen or methyl,
and their pharmaceutically acceptable salts.
Particular preference is likewise given to compounds of the general formula (I) according to the invention in which A represents the xe2x80x94CH2xe2x80x94 group.
Very particular preference is given to compounds of the general formula (I) according to the invention, in which
A represents xe2x80x94CH2xe2x80x94,
R1 represents phenyl or naphthyl,
where all of the abovementioned ring systems are optionally mono- to polysubstituted by identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, iodine, cyano, nitro, trifluoromethyl or (C1-C4)-alkoxy,
and/or are substituted by (C1-C4)-alkyl,
and/or are substituted by groups of the formulae xe2x80x94NR16COxe2x80x94R17, xe2x80x94NR18CO2xe2x80x94R19 and xe2x80x94COxe2x80x94NR20R21,
in which
R16 is hydrogen,
R17 is (C1-C8)-alkyl, which is optionally substituted by cyclopropyl, cyclopentyl, cyclohexyl, phenyl, thienyl or furyl, where the ring systems for their part may be mono- to polysubstituted by identical or different substituents from the group consisting of (C1-C3)-alkyl, (C1-C3)-alkoxy, hydroxyl, nitro, fluorine, chlorine and bromine,
R18 has the meaning of R16 given above and is identical to or different from this meaning,
R19 represents (C1-C4)-alkyl or (C3-C5)-alkenyl,
R20 and R21 are identical or different and represent hydrogen, (C2-C3)-alkenyl, (C1-C7)-alkyl or (C3-C5)-alkinyl, which are optionally substituted by phenyl, pyridyl, furyl, thienyl or pyrryl, where the ring systems are optionally substituted up to 2 times by identical or different substituents from the group consisting of (C1-C3)-alkoxy, fluorine, chlorine, bromine and (C1-C3)-alkyl,
R2 and R3 represent hydrogen or methyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34, R35 represent hydrogen,
and their pharmaceutically acceptable salts.
Very particular preference is given to the structures listed in the table below, which can be present in racemic form or enantiomerically pure: 
Moreover, we have found a process for preparing the compounds of the general formula (I) according to the invention, characterized in that compounds of the general formula (II) 
in which
D, E, R2 and R3 are as defined above
are reacted with compounds of the general formula (III),
Txe2x80x94Axe2x80x94R1xe2x80x83xe2x80x83(III)
in which
T represents halogen, preferably bromine,
and
A and R1 are as defined above,
in inert solvents and in the presence of a base,
and the substituent R1 is, if appropriate, derivatized by customary methods.
The process according to the invention can be illustrated in an exemplary manner by the formula scheme below: 
Suitable solvents are all inert solvents which do not change under the reaction conditions. These preferably include ethers, such as diethyl ether, dioxane, tetrahydrofuran, glycol dimethyl ether or diethylene glycol dimethyl ether. Particular preference is given to tetrahydrofuran.
Suitable bases are the customary inorganic or organic bases. These preferably include alkali metal hydroxides, such as, for example, sodium hydroxide or potassium hydroxide, or alkali metal carbonates, such as sodium carbonate or potassium carbonate, or sodium methoxide or potassium methoxide, or sodium ethoxide or potassium ethoxide or potassium tert-butoxide, or amides, such as sodium amide, lithium bis-(trimethylsilyl)amide, lithium diisopropylamide, or organometallic compounds, such as butyllithium or phenyllithium. Preference is given to lithium diisopropylamide and lithium bis-(trimethylsilyl)amide.
Here, the base is employed in an amount of from 1 to 5, preferably from 1 to 2 mol, based on 1 mol of the compounds of the general formula (II).
The reaction is generally carried out in a temperature range of from xe2x88x9278xc2x0 C. to reflux temperature, preferably from xe2x88x9278xc2x0 C. to +20xc2x0 C.
The reaction can be carried out under atmospheric, elevated or under reduced pressure (for example from 0.5 to 5 bar). In general, the reaction is carried out at atmospheric pressure.
Derivatizations in the context of the invention which may preferably be mentioned are reactions at the radical R1 with substituent groups (C1-C6)-alkoxy, xe2x80x94NR14R15, xe2x80x94NR16xe2x80x94COR17xe2x80x94, xe2x80x94NR18xe2x80x94CO2R19 and xe2x80x94COxe2x80x94NR20R21. Starting with the carboxylic-acid-substituted aryls, these are reacted with the corresponding amines in inert solvents and in the presence of an auxiliary. Also possible is a Curtius rearrangement in the presence of (C6H5O)2xe2x80x94PON3. Likewise, it is possible, starting from amino-substituted aryls (R1), to introduce the amide function via the corresponding acid chlorides in the presence of bases or via the corresponding carboxylic acids in the presence of an auxiliary.
The derivatizations can be illustrated in an exemplary manner by the following formula scheme: 
The amidation is generally carried out in inert solvents in the presence of a base and a dehydrating agent.
Here, suitable solvents are inert organic solvents which do not change under the reaction conditions. These include halogenated hydrocarbons, such as dichloromethane, trichloromethane, carbon tetrachloride, trichloroethane, tetrachloroethane, 1,2-dichloroethane or trichlorothylene, hydrocarbons, such as benzene, xylene, toluene, hexane, cyclohexane, or mineral oil fractions, nitromethane, dimethyl-formamide, acetonitrile or hexamethylphosphoric triamide. It is also possible to use mixtures of the solvents. Particular preference is given to dichloromethane.
Suitable bases for the derivatizations are the customary basic compounds. These preferably include alkali metal hydroxides or alkaline earth metal hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide or barium hydroxide, alkali metal hydrides, such as sodium hydride, alkali metal carbonates or alkaline earth metal carbonates, such as sodium carbonate, potassium carbonate, or alkali metal alkoxides, such as, for example, sodium methoxide or sodium ethoxide, potassium methoxide or potassium ethoxide or potassium tert-butoxide, or organic amines, such as benzyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, pyridine, triethylamine or N-methylpiperidine.
The derivatizations are generally carried out in a temperature range of from xe2x88x9220xc2x0 C. to 150xc2x0 C., preferably at from 0xc2x0 C. to 25xc2x0 C.
The derivatizations are generally carried out under atmospheric pressure. However, it is also possible to carry out the processes under reduced pressure or under elevated pressure (for example in a range from 0.5 to 5 bar).
When carrying out the derivatizations, the bases are generally employed in an amount of from 1 to 3 mol, preferably from 1 to 1.5 mol, based on 1 mol of the carboxylic acid in question.
Suitable dehydrating agents are carbodiimides, such as, for example, diisopropyl-carbodiimide, dicyclohexylcarbodiimide or N-(3-dimethylaminopropyl)-Nxe2x80x2-ethyl-carbodiimide hydrochloride, or carbonyl compounds, such as carbonyldiimidazole, or 1,2-oxazolium compounds, such as 2-ethyl-5-phenyl-1,2-oxazolium-3-sulphonate, or propanephosphoric anhydride or isobutyl chloroformate or benzotriazolyloxy-tris-(dimethylamino)phosphonium hexyfluorophosphate or diphenyl phosphonamidate or methanesulphonyl chloride, if appropriate in the presence of bases, such as triethylamine or N-ethylmorpholine or N-methylpiperidine or dicyclohexylcarbodiimide or N-hydroxysuccinimide.
Moreover, we have found a process for preparing the compounds of the general formula (Ixe2x80x2) according to the invention 
in which
A, R1, R2 and R3 are as defined above,
and
D and E together form radicals of the formulae 
in which
R33, R35, R36 and R38 represent hydrogen, and
R34 and R37 are as defined above,
characterized in that
a compound of the general formula (Ixe2x80x3) 
in which
A, R1, R2 R3, R31 and R32 are as defined above,
is isomerized in the presence of a catalyst and, if appropriate, a solvent.
The process according to the invention can be illustrated in an exemplary manner by the formula scheme below: 
Suitable solvents are, for example, alcohols.
Preference is given to n-butanol.
Suitable catalysts are transition metals, such as, for example, palladium, platinum or rhodium, preferably palladium, in an amount of from 0.01 to 1 equivalent, based on the amount of the compound of the general formula (Ixe2x80x3) used, preferably from 0.05 to 0.2 equivalents.
Very particular preference is given to palladium adsorbed on activated carbon.
The reaction is generally carried out in a temperature range from 80 to 200xc2x0 C., preferably from 100 to 150xc2x0 C.
The reaction can be carried out under atmospheric, elevated or under reduced pressure (for example from 0.5 to 5 bar). In general, the reaction is carried out under atmospheric pressure.
Moreover, the present invention relates to compounds of the general formula (II) 
in which
R2 and R3 are identical or different and represent hydrogen or (C1-C6)-alkyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34, R35, R36, R37 and R38 are identical or different and represent hydrogen, phenyl or (C1-C6)-alkyl.
Preference is given to compounds of the general formula (II), in which
R2 and R3 represent hydrogen or methyl,
and
D and E together form radicals of the formulae 
in which
R31, R32, R33, R34 and R35 represent hydrogen.
Moreover, we have found processes for preparing the compounds of the general formula (II) according to the invention 
in which
D, E, R2 and R3 are as defined above,
characterized in that in
[A] compounds of the general formula (IV) 
in which
D and E are as defined above
and
R39 represents (C1-C4)-alkyl or (C2-C4)-alkenyl, which are optionally substituted by phenyl,
the ester group is selectively reduced and the reaction product is cyclized under acidic conditions, if appropriate after prior activation of the carboxyl group to give the lactone,
or
[B] compounds of the general formula (V) 
in which
D and E are as defined above
and
R40 represents (C1-C4)-alkyl or (C3-C4)-alkenyl, which may optionally be substituted by phenyl,
the carboxyl group is selectively reduced and the reaction product is cyclized to give the lactone,
or
[C] compounds of the general formula (VI) 
in which
D and E are as defined above,
are initially reduced under suitable reduction conditions to give a hydroxylactone and subsequently reacted in an inert solvent with a compound of the general formula (VII),
R2xe2x80x2xe2x80x94Qxe2x80x83xe2x80x83(VII),
in which
R2xe2x80x2 represents (C1-C6)-alkyl, and
Q represents an alkali metal halide or alkaline earth metal halide, preferably Mg-X,
and cyclized under acidic conditions to give the corresponding lactone,
or
[D] compounds of the general formula (VI) are reacted in an inert solvent with at least two molar equivalents of a compound of the general formula (VII) and cyclized under acidic conditions to give the corresponding lactone,
or
[E] compounds of the general formula (VI) are, in an inert solvent, initially reacted with a molar equivalent of a compound of the general formula (VII), and then reacted with at least one further molar equivalent of a compound of the general formula (VIII)
R3xe2x80x2xe2x80x94Qxe2x80x2xe2x80x83xe2x80x83(VIII),
in which
R3xe2x80x2 represents (C1-C6)-alkyl and
Qxe2x80x2 has the abovementioned meaning of Q and is identical to or different from this,
and cyclized under acidic conditions to give the corresponding lactone.
The processes according to the invention can be illustrated in an exemplary manner by the formula schemes below: 
Suitable reducing agents for the process [A] are complex metal hydrides.
Preference is given to diisobutylaluminium hydride.
Suitable solvents are inert solvents, such as, for example, methylene chloride, THF, dioxane, diethyl ether, toluene, 1,2-dichloroethane.
Preference is given to methylene chloride.
The reaction is generally carried out in a temperature range of from xe2x88x9240xc2x0 C. to the reflux temperature of the solvent, preferably from 0xc2x0 C. to 30xc2x0 C.
If appropriate, the cyclization of the hydroxycarboxylic acid intermediate can be supported by activating the carboxyl group, for example using alkyl chloroformates, preferably methyl chloroformate, in the presence of a base, such as, for example, triethylamine.
A suitable method of reduction for the process [B] is a stepwise reduction by pre-activating the carboxyl group using alkyl chloroformates, preferably methyl chloroformate, in the presence of a base, such as, for example, triethylamine, followed by reduction with a complex metal hydride, such as, for example, a borohydride, preferably sodium borohydride.
Suitable solvents for the activation are inert solvents, such as diethyl ether, THF, methylene chloride. Suitable solvents for the reduction with borohydrides are, for example, alcohols, in particular methanol.
The reaction is generally carried out in a temperature range from xe2x88x9240xc2x0 C. to 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 30xc2x0 C.
Suitable reducing agents for the process [C] are complex metal hydrides having reduced reactivity, such as, for example, lithium tris-tert-butoxyaluminohydride.
Solvents which are suitable for this purpose are inert solvents, such as, for example, diethyl ether or THF.
The reaction is generally carried out in a temperature range of from xe2x88x9278xc2x0 C. to 0xc2x0 C., preferably from xe2x88x9250xc2x0 C. to xe2x88x9220xc2x0 C.
Suitable inert solvents for the reaction with the compounds of the general formulae (VII) and (VIII) in processes [C] to [E] are ethers, preferably diethyl ether or THF.
The reactions are generally carried out in a temperature range of from xe2x88x9278xc2x0 C. to 35xc2x0 C., preferably at from xe2x88x9260xc2x0 C. to 25xc2x0 C.
Suitable acids for the cyclization to the lactones are, in particular, mineral acids, such as, for example, dilute aqueous sulphuric acid or hydrochloric acid.
The compounds of the general formulae (IV) and (V) are known per se or can be prepared by customary methods.
The compounds of the general formula (I) according to the invention are suitable for use as medicaments in the treatment of humans and animals.
The compounds of the general formula (I) according to the invention are suitable for modulating metabotropic glutamate receptors and therefore influence the glutamatergic neurotransmitter system.
For the purpose of the invention, a modulator of the metabotropic glutamate receptor is an agonist or antagonist of this receptor.
The compounds according to the invention are particularly suitable as modulators of the metabotropic glutamate receptor of subtype 1, very particularly as antagonists of this receptor subtype.
Owing to their pharmacological properties, the compounds according to the invention can be used, on their own or in combination with other pharmaceuticals, for the treatment and/or prevention of neuronal damage or disorders associated with pathophysiological conditions of the glutamatergic system in the central and peripheral nervous system.
For the treatment and/or prevention of neuronal damage caused, for example, by ischaemic, thromb- and/or thrombemolic and haemorrhagic stroke, conditions after direct and indirect injuries in the area of the brain and the skull. Furthermore for the treatment and/or prevention of cerebral ischaemias after surgical interventions in the brain or peripheral organs or body parts and conditions of pathological or allergic nature accompanying or preceding them, which can lead primarily and/or secondarily to neuronal damage.
Likewise, the compounds according to the invention are also suitable for the therapy of primary and/or secondary pathological conditions of the brain, for example during or after cerebral vasospasms, hypoxia and/or anoxia of previously unmentioned origin, perinatal asphyxia, autoimmune disorders, metabolic and organ disorders which can be accompanied by damage to the brain, and also damage to the brain as a result of primary brain disorders, for example convulsive conditions and artero- and/or arteriosclerotic changes. For the treatment of chronic or psychiatric conditions such as, for example, depression, neurodegenerative disorders, such as, for example, Alzheimer""s, Parkinson""s or Huntington""s disease, multiple sclerosis, amyotrophic lateral sclerosis, neurodegeneration due to acute and/or chronic viral or bacterial infections and multiinfarct dementia.
Moreover, they can be used as pharmaceuticals for the treatment of dementias of different origin, impaired brain performance owing to old age, memory disturbances, spinal injuries, states of pain, states of anxiety of different origin, medicament-related Parkinson""s syndrome, psychoses (such as, for example, schizophrenia), brain oedema, neuronal damage after hypoglycaemia, emesis, nausea, obesity, addiction and withdrawal symptoms, CNS-mediated spasms, sedation and motor disturbances.
Furthermore, the compounds of the general formula (I) according to the invention can be used for promoting neuronal regeneration in the post-acute phase of cerebral injuries or chronic disorders of the nervous system.
They are preferably employed as pharmaceuticals for the treatment of cerebral ischaemias, craniocerebral trauma, states of pain or CNS-mediated spasms (such as, for example, epilepsy).
The modulation of substances at the metabotropic glutamate receptor (direct or indirect effect on the coupling efficiency of the glutamate receptor to G-proteins) can be examined using primary cultures of granular cells from the cerebellum. Electrophysiological measurements on these cell cultures in the xe2x80x9ccell attachedxe2x80x9d mode show that L-type Ca2+-channels in this preparation are activated by mGluRl-receptors (J. Neurosci. 1995, 15, 135), whereas they are blocked by group II receptors (J. Neurosci. 1994, 14, 7067-7076). By an appropriate experimental arrangement, it is possible to monitor the modulatory effect of pharmacological test substances on glutamate receptors. Detailed examination of subtype specificity under controlled conditions can be carried out by injecting the appropriate mGluR subtype DNA into Xenopus oocytes (WO 92/10583).
Permanent Focal Cerebral Ischaemia in the Rat (MCA-O)
Under isoflurane anaesthesia, the middle cerebral artery is exposed on one side and the latter and its side branches are irreversibly sealed by means of electrocoagulation. As a result of the intervention a cerebral infarct is formed. During the operation, the body temperature of the animal is kept at 37xc2x0 C. After wound closure and wearing off of the anaesthesia, the animals are again released into their cage. Substance administration is carried out according to different time schemes and via different administration routes (i.v., i.p.) after occlusion. The infarct size is determined after 7 days. To do this, the brain is removed, worked up histologically and the infarct volume is determined with the aid of a computer-assisted analysis system.
Subdural Haematoma in the Rat (SDH)
Under anaesthesia, the animal""s own blood is injected subdurally on one side. An infarct is formed under the haematoma. Substance administration is earned out according to different time schemes and via different administration routes (i.v., i.p.).
The determination of the infarct size is carried out as described in the model of permanent focal ischaemia in the rat (MCA-O).
Using the method described in NeuroReport 1996, 7, 1469-1474, it is possible to test for antiepileptic activity.
The suitability of the compounds according to the invention for treating schizophrenia can be determined by the methods described in Science 1998, 281, 1349-1352 and Eur. J. Pharmacol. 1996, 316, 129-136.
The present invention also includes pharmaceutical preparations which, in addition to inert, non-toxic, pharmaceutically suitable auxiliaries and excipients, comprise one or more compounds of the general formula (I), or which consist of one or more active compounds of the formula (I), and processes for producing these preparations.
In these preparations, the active compounds of the formula (I) should be present in a concentration of from 0.1 to 99.5% by weight, preferably from 0.5 to 95% by weight, of the total mixture.
In addition to the active compounds of the formula (I), the pharmaceutical preparations may also comprise other pharmaceutical active compounds.
The abovementioned pharmaceutical preparations can be prepared in a customary manner by known methods, for example with the auxiliary(ies) or excipient(s).
In general, it has proved advantageous to administer the active compound(s) of the formula (I) in total amounts of about 0.01 to about 100 mg/kg, preferably in total amounts of about 1 mg/kg to 50 mg/kg, of body weight per 24 hours, if appropriate in the form of a plurality of individual administrations, to achieve the desired result.
However, if appropriate, it may be advantageous to depart from the amounts mentioned, namely depending on the type and on the body weight of the object treated, on the individual response towards the medicament, the nature and severity of the disorder, the manner of formulation and administration, and the time or interval at which administration takes place.
General Section
Starting Materials